What is the test for issuing a search warrant for a fourth search?

The search also was not legal under the traditional test requiring both probable cause and exigent circumstances. At the time of the fourth search, there were no exigent circumstances present. Although the risk of explosion can amount to exigent circumstances, see United States v. Echegoyen, 799 F.2d 1271, 1278-79 (9th Cir. 1986), that risk had been defused by the time the fourth search occurred. Therefore, the fourth search was illegal.

2. Legality of the Search Warrant

A magistrate's issuance of a search warrant is reviewed for clear error and we must uphold such a warrant "so long as the [magistrate] had a `substantial basis' for concluding probable cause existed based on the totality of the circumstances." Bertrand, 926 F.2d at 841 (citation omitted). In analyzing the magistrate's decision, however, we must excise the portion of the affidavit in support of the warrant application containing information that was obtained during the illegal fourth search. See United States v. Reed, 15 F.3d 928, 933 (9th Cir. 1994) ("A reviewing court should excise the tainted evidence and determine whether the remaining untainted evidence would provide a neutral magistrate with probable cause to issue a warrant.") (internal quotation marks and citation omitted).